Vertical handover

• US 20080064401A1
• Filed: 10/31/2006
• Published: 03/13/2008
• Est. Priority Date: 09/13/2006
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Yang, Fan, Forssell, Mika, Sarolahti, Pasi
• Granted Patent: US 8,244,248 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface

Abstract

A vertical handover decision to perform a seamless vertical handover of a wireless apparatus from a current access network to a target access network is established. When deciding to perform the vertical handover from the current access network to the target access network it can be considered whether an intermediate access network could be used. It can be decided that first a seamless vertical handover is performed from the current access network to an intermediate access network, and subsequently a seamless vertical handover from the intermediate access network to the target access network is performed.

Claims

1. A method for vertical handover comprising:

establishing a decision to perform a vertical handover of a wireless apparatus from a current access network to a target access network; and

further deciding to perform the vertical handover from the current access network to the target access network via at least one intermediate access network.

2. The method of claim 1, the method comprising:

establishing the decision to perform the vertical handover based on at least one beforehand stored criterion.

3. The method of claim 1, wherein the intermediate access network and the target access network are selected from a group of access networks which the wireless apparatus sees at the time of decision making.

4. The method of claim 1, wherein the method comprises:

deciding, by a decision unit, that the vertical handover from the current access network to the target access network is performed in a seamless manner by

first performing a seamless vertical handover from the current access network to an intermediate access network; and

subsequently performing a seamless vertical handover from the intermediate access network to the target access network.

5. The method of claim 4, wherein seamless vertical handover comprises a vertical handover without causing substantial interruption in application level connections.

6. The method of claim 1, wherein the method comprises deciding to perform the vertical handover via said at least one intermediate access network if the current access network and target access network can not be simultaneously active for the wireless apparatus.

7. The method of claim 1, wherein the method comprises deciding that the intermediate access network is used for waiting when the wireless apparatus sees the target access network but access to the target access network is temporarily unavailable.

8. The method of claim 1, wherein the method comprises:

performing a vertical handover from the current network to an intermediate network;

checking the characteristics of the target network while being in the intermediate network; and

making a final decision whether to perform handover from the intermediate network to the target access network only after the characteristics of the target network have been checked.

9. An apparatus comprising:

a decision unit configured to establish a decision to perform a vertical handover of a wireless apparatus from a current access network to a target access network, wherein

the decision unit is further configured to decide that the vertical handover from the current access network to the target access network is performed via at least one intermediate access network.

10. The apparatus of claim 9, the apparatus comprising:

a memory for storing beforehand at least one criterion based on which the decision to perform the vertical handover is established.

11. The apparatus of claim 9, wherein the decision unit is configured to select the intermediate access network and the target access network from a group of access networks which the wireless apparatus sees at the time of decision making.

12. The apparatus of claim 9, wherein the decision unit is configured to decide that the vertical handover from the current access network to the target access network is performed in a seamless manner by

first performing a seamless vertical handover from the current access network to an intermediate access network;

and

subsequently performing a seamless vertical handover from the intermediate access network to the target access network.

13. The apparatus of claim 12, wherein seamless vertical handover comprises a vertical handover without causing substantial interruption in application level connections.

14. The apparatus of claim 9, wherein the decision unit is configured to decide that the vertical handover is performed via said at least one intermediate access network if the current access network and target access network can not be simultaneously active for the wireless apparatus.

15. The apparatus of claim 9, wherein the decision unit is configured to decide that the intermediate access network is used for waiting when the wireless apparatus sees the target access network but access to the target access network is temporarily unavailable.

16. The apparatus of claim 9, wherein the apparatus is configured perform a vertical handover from the current network to an intermediate network, and wherein the decision unit is

configured to check the characteristics of the target network while being in the intermediate network;

and

configured to make a final decision whether to perform handover from the intermediate network to the target access network only after the characteristics of the target network have been checked.

17. The apparatus of claim 9, wherein the apparatus is said wireless apparatus.

18. The apparatus of claim 9, wherein the apparatus is a network-based apparatus, such as a network server.

19. A method for vertical handover comprising:

establishing a decision to perform a vertical handover of a wireless apparatus from a current access network to a target access network;

making a distinction between seamless and non-seamless vertical handovers when establishing the decision; and

selecting the target access network from a group of available target networks on the basis the vertical handover becoming seamless.

20. The method of claim 19, the method comprising:

establishing the decision to perform the vertical handover based on at least one beforehand stored criterion.

21. The method of claim 19, wherein the target access network is selected from a group of access networks which are available for handover at the time of decision making.

22. The method of claim 19, wherein seamless vertical handover comprises a vertical handover without causing substantial interruption in application level connections.

23. An apparatus comprising:

a decision unit configured to establish a decision to perform a vertical handover of a wireless apparatus from a current access network to a target access network, wherein

the decision unit is further configured to make a distinction between seamless and non-seamless vertical handover when establishing the decision, and to select the target access network from a group of available target networks on the basis that the vertical handover becomes seamless.

24. The apparatus of claim 23, the apparatus comprising:

a memory for storing beforehand at least one criterion based on which the decision to perform the vertical handover is established.

25. The apparatus of claim 23, wherein the decision unit is configured to select the target access network from a group of access networks which are available for handover at the time of decision making.

26. The apparatus of claim 23, wherein seamless vertical handover comprises a vertical handover without causing substantial interruption in application level connections.

27. The apparatus of claim 23, wherein the apparatus is said wireless apparatus.

28. The apparatus of claim 23, wherein the apparatus is a network-based apparatus, such as a network server.